Currently, the wireless paging service comprises a numeric paging, which transmits numeric messages, and an alphanumeric paging, which transmits simple letter messages. However, since it is limited to transmit information by numbers or letters, users prefer to use a voice message being capable of expressing unique emotion of human, and the voice mailbox service using the wireless paging network is a kind of a form to satisfy such need. Herein, the voice mailbox service is defined that a sender makes a phone call to leave a voice message in the voice mailbox, the arrival of the voice message is informed to the terminal of the receiver, and the receiver hears the messages by making a phone call to the voice mailbox.
Hereinafter, the most general method of transmitting the voice message of the conventional art will be explained.
First of all, the access to the mobile communication supplementary service proceeds with by a general mobile communication call process, and when the terminal is in the state incapable of receiving, a voice paging service is operated. That is, when a call connection is requested between terminals for transmitting a voice message, the mobile switch requests the location to HLR by using a Location Request message, and the HLR confirms the location from VLR (Visitor Location Resistor) of the visiting place in which the terminal currently locates, and then transmits to the mobile communication switch.
The mobile switch sets a communication path to the visiting place switch, and then performing the paging to the mobile communication terminal. If the terminal sends a paging responding message, a two-way real time phone call is carried out as the user wishes.
However, if the terminal is in the area incapable of receiving or the power is off, the visiting place mobile communication switch connects the communication path to the voice paging center, so that a sender can leave a voice message in the voice paging center. Thereafter, the voice paging center waits and re-transmits the message by re-transmission algorithm, and if the terminal power is off and a registered message is received from the terminal via the HLR, the voice message transmission starts.
However, such voice message transmission has the structure that the voice information of the sender is stored in the voice paging center and the receiver unilaterally hears the stored voice information. Thus, there is no way for the receiver to transmit the reply voice message to the sender's terminal in response to the sender's voice message without the sender's number. Thus, it causes a lot of inconvenience in using the system. Furthermore, under the rapidly changing environment, the conventional voice message system is the system against the current trend which requires the real time network, and such system has a problem of lowering the applicability of the network.